Echinacea Overview

The decorative plant Echinacea purpurea, or purple coneflower, has been one of the most popular herbal medications in both the United States and Europe for over a century.

Native Americans used the related species Echinacea angustifoliafor a wide variety of problems, including respiratory infections and snakebite. Herbal physicians among the European colonists quickly added the herb to their repertoire. Echinacea became tremendously popular toward the end of the nineteenth century, when a businessman named H.C.F. Meyer promoted an herbal concoction containing E. angustifolia. The garish, exaggerated, and poorly written nature of his labeling helped define the characteristics of a "snake oil" remedy.

However, serious manufacturers developed an interest in echinacea as well. By 1920, the respected Lloyd Brothers Pharmaceutical Company of Cincinnati, Ohio, counted echinacea as its largest-selling product. In Europe, physicians took up the American interest in E. angustifoliawith enthusiasm. Demand soon outstripped the supply coming from America, and, in an attempt to rapidly plant echinacea locally, the German firm Madeus and Company mistakenly purchased a quantity of Echinacea purpureaseeds. This historical accident is the reason why most echinacea today belongs to the purpureaspecies instead of angustifolia. Another family member, Echinacea pallida, is also used.

Echinacea was the number one cold and flu remedy in the United States until it was displaced by sulfa antibiotics. Ironically, antibiotics are not effective for colds, while echinacea appears to offer some real help. Echinacea remains the primary remedy for minor respiratory infections in Germany, where over 1.3 million prescriptions are issued each year.

Reducing the Symptoms and Duration of Colds

Double-blind, placebo-controlled studies enrolling a total of more than 1,000 individuals have found that various forms and species of echinacea can reduce cold symptoms and help you get over a cold faster. ¹ The best evidence regards products that include the above-ground portion of E. purpurea. ² For example, in one double-blind, placebo-controlled trial, 80 individuals with early cold symptoms were given either an above-ground E. purpureaextract or placebo. ³ The results showed that individuals who were given echinacea recovered significantly more quickly: just 6 days in the echinacea group versus 9 days in the placebo group.

Another study found evidence that above-ground E. purpureacan reduce the severity of cold symptoms, but that E. purpurearoot may not be effective. In this double-blind trial, 246 individuals with recent onset of a respiratory infection were given either placebo or one of three E. purpureapreparations: two formulations of a product made of 95% above-ground herb (leaves, stems, and flowers) and 5% root, and one made only from the roots of the plant. ⁴ The results showed significant improvements in symptoms such as runny nose, sore throat, sneezing, and fatigue, with the above-ground preparations, but the root preparation was not effective.

Symptom reduction with a whole plant formulation of E. purpureawas seen in a double-blind, placebo-controlled study of 282 people. ⁵ However, another double-blind, placebo-controlled study of above-ground E. purpurea, enrolling 120 people, failed to find benefits as compared to placebo treatment. ⁶ An even larger trial (407 participants) failed to find a widely used above-ground E. purpureaextract helpful for treating children with respiratory infections. ⁷ The reasons for these negative outcomes are unclear.

In other studies, benefits were seen with a preparation of E. pallidaroot ⁸ and an herbal beverage tea containing above-ground portions of E. purpureaand E. angustifolia(as well as some E. purpurearoot extract). ⁹ A double-blind, placebo-controlled study failed to find benefit with a dry herb product consisting largely of E. purpurearoot and E. angustifoliaroot. ¹⁰ Another study failed to find benefit with E. angustifoliaroot extract. ¹¹ The bottom line: at present, the best supporting evidence for echinacea involves the above-ground portion or whole plant extract of E. purpurea, but even here the results are less than fully consistent.

"Aborting" a Cold

A double-blind study suggests that echinacea cannot only make colds shorter and less severe, it might also be able to stop a cold that is just starting. ¹² In this study, 120 people were given E. purpureaor a placebo as soon as they started showing signs of getting a cold.

Participants took either echinacea or placebo at a dosage of 20 drops every 2 hours for 1 day, then 20 drops 3 times a day for a total of up to 10 days of treatment. The results were promising. Fewer people in the echinacea group felt that their initial symptoms actually developed into "real" colds (40% of those taking echinacea versus 60% taking the placebo actually became ill). Also, among those who did come down with "real" colds, improvement in the symptoms started sooner in the echinacea group (4 days instead of 8 days). Both of these results were statistically significant.

Preventing Colds

Several studies have attempted to discover whether the daily use of echinacea can prevent colds from even starting, but the results have not been promising.

In one double-blind, placebo-controlled trial, 302 healthy volunteers were given an alcohol tincture containing either E. purpurearoot, E. angustifoliaroot, or placebo for 12 weeks. ¹³ The results showed that E. purpureawas associated with perhaps a 20% decrease in the number of people who got sick, and E. angustifoliawith a 10% decrease. However, the difference was not statistically significant. This means that the benefit, if any, was so small that it could have been due to chance alone.

Another double-blind, placebo-controlled study enrolled 109 individuals with a history of four or more colds during the previous year, and gave them either E. purpureajuice or placebo for a period of 8 weeks. ¹⁴ No benefits were seen in the frequency, duration, or severity of colds. (Note: This paper is actually a more detailed look at a 1992 study widely misreported as providing evidence of benefit. ¹⁵ )

Similar results were seen in four other studies as well, enrolling a total of more than 350 individuals. ¹⁶ A study often cited as evidence that echinacea can prevent colds actually found no benefit in the 609 participants taken as a whole. ¹⁷ Only by looking at subgroups of participants (a statistically questionable procedure) could researchers find any evidence of benefit, and it was still slight.

However, a recent study using a combination product containing echinacea, propolis , and vitamin C did find preventive benefits. ¹⁸ In this double-blind, placebo-controlled study, 430 children age 1 to 5 years were given either the combination or placebo for 3 months during the winter. The results showed a statistically significant reduction in frequency of respiratory infections. It is not clear which components of this mixture were responsible for the apparent benefits seen.

Echinacea is usually taken at the first sign of a cold and continued for 7 to 14 days. Longer-term use of echinacea is not recommended. The best (though not entirely consistent) evidence supports the use of products made from the above-ground portions of E. purpurea(specifically, flowers, leaves and stems); E. pallidaroot has also shown promise, but E. purpurearoot appears to be ineffective.

The typical dosage of echinacea powdered extract is 300 mg 3 times a day. Alcohol tincture (1:5) is usually taken at a dosage of 3 to 4 ml 3 times daily, echinacea juice at a dosage of 2 to 3 ml 3 times daily, and whole dried root at 1 to 2 g 3 times daily. There is no broad agreement on what ingredients should be standardized in echinacea tinctures and solid extracts.

Note: A survey of available echinacea products found many problems. ¹⁹ In this 2003 analysis, about 10% had no echinacea at all; about half were mislabeled as to the species of echinacea present; more than half the standardized preparations did not contain the labeled amount of standardized constituents; and the total milligrams of echinacea stated on the label generally had little to do with the actual milligrams of herb present. A subsequent analysis performed in 2004 by the respected testing organization, ConsumerLab.com, also found many problems. ²⁰ Many herbalists feel that liquid forms of echinacea are more effective than tablets or capsules, because they feel that part of echinacea's benefit is due to activation of the tonsils through direct contact. ²¹ However, there is no real evidence to support this contention.

Finally, goldenseal is frequently combined with echinacea in cold preparations. However, there is not a shred of evidence that oral goldenseal stimulates immunity, nor did traditional herbalists use it for this purpose. ²²

1. Dorn M. Plant immunostimulant alleviates symptoms of the common cold. Double-blind study involving 100 patients [translated from German]. Natur und Ganzheitsmedizin. 1989;2:314-319.
2. Linde K, Barrett B, Wölkart K, Bauer R, Melchart D. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. (1):CD000530.
3. Schulten B, Bulitta M, Ballering-Bruhl B, et al. Efficacy of Echinacea purpurea in patients with a common cold. A placebo-controlled, randomised, double-blind clinical trial. Arzneimittelforschung. 2001;51:563-568.
4. Brinkeborn R, Shah D, Geissbuhler S, et al. Echinaforce in the treatment of acute colds. Results of a placebo-controlled double-blind study carried out in Sweden. Schweiz Zschr Ganzheits Medizin. 1998;10:26-29.
5. Goel V, Lovlin R, Barton R, et al. Efficacy of a standardized echinacea preparation (EchinilinTM) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial. J Clin Pharm Ther. 2004;29:75-84.
6. Yale SY, Liu K. Echinacea purpurea therapy for the treatment of the common cold. Arch Intern Med. 2004;164:1237-1241.
7. Taylor JA, Weber W, Standish L, Quinn H, Goesling J, McGann M, Calabrese C. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA. 290(21):2824-30.
8. Dorn M, Knick E, Lewith G. Placebo-controlled double-blind study of Echinacea pallidae radix in upper respiratory tract infections. Complement Ther Med. 1997;5:40-42.
9. Lindenmuth GF, Lindenmuth EB. The efficacy of echinacea compound herbal tea preparation on the severity and duration of upper respiratory and flu symptoms: a randomized, double-blind placebo-controlled study. J Altern Complement Med. 6(4):327-34.
10. Barrett BP, Brown RL, Locken K, Maberry R, Bobula JA, D'Alessio D. Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 137(12):939-46.
11. Turner RB, Bauer R, Woelkart K, Hulsey TC, Gangemi JD. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med. 353(4):341-8.
12. Hoheisel O, Sandberg M, Bertram S, et al. Echinagard treatment shortens the course of the common cold: a double-blind, placebo-controlled clinical trial. Eur J Clin Res. 1997;9:261-268.
13. Melchart D, Walther E, Linde K, Brandmaier R, Lersch C. Echinacea root extracts for the prevention of upper respiratory tract infections: a double-blind, placebo-controlled randomized trial. Arch Fam Med. 7(6):541-5.
14. Grimm W, Muller H. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med. 1999;106:138-143.
15. Schoneberger D. The influence of immune-stimulating effects of pressed juice from Echinacea purpurea on the course and severity of colds. (Results of a double-blind study) [translated from German]. Forum Immunol. 1992;8:2-12.
16. Calabrese C. Bastyr University. Unpublished communication.
17. Schmidt U, Albrecht M, Schenk N. Immunostimulator decreases the frequency of influenza-like syndromes. Double-blind placebo-controlled trial on 646 students of the University of Cologne [in German; English abstract]. Natur und Ganzheitsmedizin. 1990;3:277-281.
18. Cohen HA, Varsano I, Kahan E, Sarrell EM, Uziel Y. Effectiveness of an herbal preparation containing echinacea, propolis, and vitamin C in preventing respiratory tract infections in children: a randomized, double-blind, placebo-controlled, multicenter study. Arch Pediatr Adolesc Med. 158(3):217-21.
19. Gilroy CM, Steiner JF, Byers T, Shapiro H, Georgian W. Echinacea and truth in labeling. Arch Intern Med. 163(6):699-704.
20. ConsumerLab.com Product Review: Echinacea. Consumer Lab website. Available at: http://www.consumerlab.com/results/echinacea.asp. Accessed May 5, 2006.
21. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine. 3rd ed. Berlin, Germany: Springer-Verlag; 1998:278.
22. Bergner P. Goldenseal and the common cold: The antibiotic myth. Med Herbalism. 1996/1997;8(4):1, 4-6.